Watch casing



FIG. 1 is a top perspective view of a watch casing showing my new design;

FIG. 2 is a right side elevational view thereof, the left side being a mirror image;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a first end elevational view thereof;

FIG. 6 is a second end elevational view thereof; and,

FIG. 7 is a bottom perspective view thereof.

The dotted lines are intended to show features that are environmental only and form no part of the claimed design. 

The ornamental design for a watch casing, as shown and described. 